In the production of insulation board, it is common to incorporate a blown asphalt binder with the wood particulate matter, usually in the form of sawdust, shavings, etc. In such a process, the asphalt is melted, usually at temperatures of above 225.degree. F., and the molten material is solidified by being injected into cold water. The solidifed asphalt is then crushed and added to a slurry of wood or other cellulosic particles. Obviously substantial energy is required to heat the asphalt and maintain it in the molten state during such a procedure. It is to the elimination of using a molten asphalt and the heating and energy uses that the present invention is directed.